Conventionally used is a lubricating pump installed on a grease can to supply grease in the grease can to a metering valve or the like on machinery and equipment at an oiling site (see Patent Literature 1).
In the lubricating pump of the Patent Literature 1, a lid on which a suction unit is integrally arranged can be placed on a grease can to close an opening of the can. A suction pipe extends downward from the lid and is in communication with the suction unit. A follower plate is vertically movably suspended by ball chains from the suction pipe, has a central through bore through which the suction pipe fittingly extends and is contacted at an outer periphery thereof with an inner surface of the grease can.
Upon use of such lubricating pump, the flower plate is fitted into the opened grease can so as to be closely contacted with the grease in the grease can, and the lid with the suction unit is fitted on an upper end of the grease can with the suction pipe extending through the central through bore of the follower plate. Driving of the suction unit with such set state causes the grease in the grease can to be sucked through the suction pipe to the metering valve at the oiling site. Decrease of the grease in the grease can is accompanied by lowering of the follower plate, and the grease supply is stopped when the follower plate is lowered to a bottom of the grease can. In the lubricating pump of Patent Literature 1, almost all of the grease in the grease can may be sucked and supplied by use of the follower plate. After the grease supply is finished, the suction unit is lifted up to raise the suction pipe, and the follower plate is pulled up and taken out from the empty grease can.
However, the suction of the grease in the grease can by the suction unit may cause minute bubbles intermingling in the grease to be agglomerated into large-diameter bubbles. Such large-diameter bubbles supplied to the metering valve may disadvantageously make the grease supply intermittent by the metering valve to the machinery and equipment at the oiling site, resulting in serious failure of unmaintained stable lubricating performance to the machinery and equipment which are required to be always volumetrically supplied with the grease in a minute amount. There is also a problem that, after the grease can is opened, the grease therein is changed in quality by oxidization through contact with ambient air and oil separation through gravity.
There is a grease supplying device for prevention of the above-mentioned large-diameter bubbles from being produced (see Patent Literature 2).
In the grease supplying device in Patent Literature 2, grease in a grease can is supplied by a pressure pump to a bubble dividing device in a grease regulation unit. In the bubble dividing device, the grease from the pressure pump is passed through minute passages of a porous member to divide the bubbles. The bubbles of the grease passed through the minute passages are further divided by a porous moving member moving along an outlet surface of the porous member. The grease with the bubbles micronized by the division is supplied to the metering valve. The grease regulation unit is provided with a porous nozzle through which the storage tank is filled with the grease branched from an outlet of the bubble dividing device via a circulation passage so as to attain micronization of the bubbles and mixing of the grease as well as a supply pump which supplies the grease in the storage tank to the metering valve via the bubble dividing device.
According to the grease supplying device of Patent Literature 2 mentioned above, the grease is supplied with the bubbles therein being micronized by the bubble dividing device, so that prevented is the problem of intermittent grease supply by the metering valve to the machinery and equipment at the oiling site. Moreover, the circulation of the grease to the closed storage tank contributes to effective mixing of the grease and prevents change in quality of the grease such as oil separation.